A duplex saw is a commonly used power tool and widely used in the field of machinery manufacturing and other fields. The duplex saw can be functionally converted between the two working states of a miter saw and a table saw, and is very convenient to use. There are two commonly used solutions in the prior art: one is a commonly used duplex saw structure, generally, the height of a motor and a saw blade are fixed, the function of sawing is achieved by adjusting the height of a cutting working platform; the other is that a panel of the cutting working platform is fixed, the lift of the saw blade is achieved by lifting or rotating a motor assembly to realize the function of cutting.
The above two solutions are flawed in use. For the first solution, during the process of adjusting the height of the cutting working platform, the relative position between a panel of the cutting working platform and the saw blade can be changed, in order to ensure a smooth height adjustment, a guiding mechanism generally has a relative large gap and maintains poorly the stability of a relative position, thus greatly reducing the precision of the cutting. since the relative position between the motor and the saw blade is fixed, the thickness of the motor in the vertical direction determines the cutting ability of the cutting and the inclined cutting in height; in fact, most manufacturers make a very flat motor assembly, which can slightly increase the cutting height of the cutting and the inclined cutting, however, this is very detrimental to the design of the motor and a motor shell.
For the second solution, there are two ways to lift the motor assembly via a lift mechanism, one is that the motor is lifted vertically or rotated up and down along one fulcrum outside the motor assembly, the principle of this lifting method is similar to that of the first one, the movement of the motor is just used for replacing the movement of a platen; because of a motor lift guiding machining accuracy assurance, the relative accuracy during the lift can be improved to a certain extent, however, the thickness of the motor assembly still affects the cutting capacity; in addition, the motor's lifting mechanism greatly increases the complexity of the mechanism. The other is that the whole motor assembly is rotated about the center of the motor, the eccentricity formed by the center distance of the rotation of the gear is used for switching the inclined cutting and the cutting, for example, china patent No. CN205020940 discloses a duplex saw, because the motor needs to be rotated, the entire rotated trajectory of the motor shape is round, therefore, a height of a whole machine is increased relative to the conventional flat motor assembly, the increase of a package volume affects not only a transport cost but also a storage space. furthermore, an output shaft of this structure and a gear only can be positioned within an outer circle of the motor, an eccentricity distance is limited, the eccentricity distance determines the maximum height of the saw blade from the platen to the upper portion of the platen and can not provide a enough lift space, thus limiting the cutting capacity. to improve the cutting capacity, an outer circle of the motor can only be increased, this causes an excessive machine size and needs to increase the mechanical properties of a machine frame structure that supports the motor assembly, furthermore, inlet and outlet lines of a power are wound, worn and other risks during the rotation of the motor.
Regardless of which solution used, the saw blade in a non-work area in the technical solution in the prior art is exposed, it is difficult to control complete protection, when the cutting is carried out in the non-work area, the non-work area is below the platen while the non-work area is above the platen during the inclined cutting, based on safety requirements, the saw blade in the non-work area needs be completely protected. therefore, it is common practice to add an additional shield in the non-work area as an attachment for protection, special measures need be taken to prevent the attachment from being discarded, so the structure is complicated and inconvenient to operate.
For the above problems, many manufacturers and people of insight have carried out development and research, but so far no more ideal product is available.